Carburetor



Jan. 22, 1952 ARNQLD 2,583,406

CARBURE'I'OR Filed April 6, 1948 2 S!-1EETS-Sl-IEET 1 /22 V I W90. 85 A9 1 Lucien T. Arno/d INVENTOR.

mun paw 13% Patented Jan. 22, 1952 CARBURETOR Lucien T. Arnold, Pensacola, Fla.

Application April 6, 1948, Serial No. 19,260

1 Claim. (Cl. 261-439) This invention relates to a carbureter for use in internal combustion engines and has for its primary object to maintain a predetermined and correctly proportioned air and fuel mixture for delivery to the engine, to insure greater smoothness in operation, to prevent back-firing due to an improper mixture and poor fuel composition, and to obtain maximum efiiciency and proper sparking with an economical saving in fuel.

An improper feature of this invention resides in the provision of a square casing, having suitably journaled therein a square vacuum valve which, responsive to the operation of the engine, maintains a proper fuel mixture and delivers same under predetermined conditions to the engme.

Another important feature of this invention resides in the provision of a control fuel inlet and air-admittance chamber, the control element being responsive to the operation of the engine, and in non-operation thereof to a thermostatic control.

Another object of this invention resides in the provision of a carburetor, which is economical to manufacture, efficient and reliable in operation, responsive to automatic control, and .durably constructed.

These and ancillary objects and other meritorious features are attained by this invention, a

preferred embodiment of which is set forth in n tional type of intake manifold, being secured thereon by bolt and nut assemblies 24.

Suitably secured in the upper portion [4 adjacent the air inlet end is a fuel inlet assembly 26 which is connected by a suitable connection 28 to th fuel pump, not shown. The assembly 26 comprises a valve housing 30 which is positioned vertically in the passageway l2 and spaced from the side walls of the casing by a lateral extension 32, having an extending exteriorly threaded portion 34, which protrudes beyond the walls through a casing slot or opening 36. Means are provided for vertically adjusting the assembly and includes a flange 38 formed on the lateral extension 32 and. abutting against the interior of the casing wall, with a complimentary plate the following description and illustrated in the accompanying drawings, wherein:

Figure 1 is a vertical sectional view of an improved carburetor, constructed in accordance with the principles of this invention, showing some of the actuating structure in elevation;

Figure 2 is a top plan view of this invention;

Figure 3 is a transverse sectional. view taken substantially on the plane of lines 33 of Figure 1;

Figured is a vertical sectional view, showing some of the components in elevation; and

Figure 5 is a view in perspective of the needle valve, employed to control the admission of fuel to the casing. 1

Referring now more particularly to the drawings wherein similar characters of reference designate corresponding parts throughout, the numeral l0 designates a square carburetor casing, having a vertical passageway l 2 therein, with an upper end portion l4 defining an air inlet chamber l6 and a coaxially reduced lower portion 18., forming an outlet or engine chamber, 20. A flange 22 is disposed at the end of the outlet casing 18 and is adapted to seat on any conven- 40 received on the threaded terminus and positioned against the exterior surface of the wall. A locking nut 42 is suitably secured on the threaded extremity and bears against the exterior plate 40, securing the lateral extension in selected vertical placement. A cap 44 is threaded on the terminus of the extension 34 and-secures the fuel connecting tube 28 in inserted position within an inlet bore 46 disposed in the lateral extension. The inlet'bore 46 transversely communicates with a vertical passageway or bore 43 disposed in the valve block 30, the bore 48 being enlarged outwardly by the opposed shoulders 5B and terminating in a square guide bore 60. Reciprocably guided and fitted within the vertical bore 48 and adapted to control the flow of fluid i therethrough, responsive to automatic means, is a needle valve 52 having a stem 54, preferably square in cross section, and having a bifurcated extremity :56, with transversely aligned apertures 58 disposed in the bifurcations. Extending from the stem 54 opposite the bifurcations 56 is a needle portion 62, with the secured portion 64 preferably circular and coaxially reduced from the sides of the square stem 54, defining a valve seat 66. The bifurcations 56 have a link '10 received therein and pivotally supported by a pin 12. The opposite extremity of the link is suitably received on a square valve gate '74 which is formed to correspond to the interior configuration of the upper casing 14 and controls the vertical passageway Hi, the valve gate 14 being secured by screws 16 to a shaft 18 which is transversely journaled in the casing. An attaching plate is secured by suitable means, such as bolts 82, to the upper face of the square gate 14. Raised from one end of the plate 80 are cooperating apertured ears 85, within which the apertured extremity of the connecting link I is pivoted by a transverse pin 84.

Transversely journaled in the reduced square lower portion I8 is a throttle shaft 86, to the under side of which is secured by securing means 88 the square butterfly valve or gate 90, which is manually actuated by a cable or rod 94 secured to the extending end of a crank lever 96 by stop assembly 98 secured on the extending end thereof. The lateral terminus I00 of the lever 86 is suitably apertured and received on a travel limit pin I02, with the angular portion pivoted to the extending portion of the throttle shaft 86 outside the casing.

Means are provided to control the automatic vacuum actuating gate I4, which is responsive to the vacuum created in the intake manifold when the engine is in operation, whenever the engine is cold, and includes a conventional thermostat,

I04 having one end secured to a U-shaped attaching bracket, the opposite arm of the bracket being held in position by the bolt assembly 24 on the flange 22 of the lower casing l8. A rod I06 extends vertically from the thermostat and is inserted in an aperture in the end of a bar I08, which is suitably pivoted oifcenter, as at IIO, to a triangular bracket plate II2, which is bolted to the side of the casing by bolt assemblies H4. The opposite end of the pivot bar I08 is suitably apertured and connected by resilient means II6, such as a coil or tension spring, to a similar bar II8, which has its opposite terminus received on the extending end of the shaft I8, with an adjusting set screw I provided.

A vacuum idle control mechanism is provided and comprises a connection I22 which communicates between the lower casing I8 and a bellows I24, which is suitably secured to the upper portion I4 by means of the extending bracket arm I28. A pin I28 is received in the bifurcated extremity of an adjusting bar I30, the bar I30 being centrally pivoted between a pair of upstanding apertured ears I 32 by a pin I34, the apertured ears I 32 being integrally carried by an angle bracket I36 which is suitably secured to the outer wall ofthe upper portion I4 by means of the bolt assembly I4I. Suitably secured to the pivoted bar I30 is an adjusting screw I40, which is adapted to serve as a stop medium for the bar I z 8, attached to the shaft I8 of the valve gate In operation, assuming the engine to be cold, the bellows type thermostat I04 is contracted, and the lever I08 is moved around the horizontal axis I I 0, allowing the lever I I8 to move upwardly, with the tension removed from the resilient means H8. The upward movement of the lever II 8 causes the valve gate I4 to move downwardly on the shaft I40 and throu h the linkage I0, coincidentally and correspondingly moves the needle valve. Unseating of the needle valve allows the fuel to enter through the fuel inlet bores 48 and and to mix with the air entering from the air admission chamber I6, whereupon manual actuation, through the rod 94, causes the throttle valve 90 to p ss the fuel mixture through the lower casing I8 on into the cylinders.

When the engine is running at idling speed, a vacuum is created in the intake manifold and when the throttle valve 90 is actuated, the vacuum causes the valve gate I4 to move downwardly, admi ting the fuel and the air, as noted above, the mixture pas ing through the passageway I2.

The vacuum idle control mechanism is adapted to enable the adjusting screw I40 to serve as a stop medium for the vacuum gate I4 and allows the vacuum gate to remain open a sufiicient period of time to allow a slight amount of fuel to reach the engine, the slight admission of fuel enabling the engine to maintain the idling speed. When the motor stops, correspondingly, there is no vacuum in the manifold and the bellows I24 expands to cause the screw I40 to move away from the lever II8 as the rod I28 moves the lever upwardly, causing the valve gate I4 to be moved upwardly by the spring I I6, shutting off the fuel inlet 46 and the air admission chamber I6.

To compensate for a backfire, caused by faulty timing, wet ignition system or the like causations, a pressure release valve I42 is provided. The valve I42is disposed in the casing I0 below the valve gate I4 and comprises a, head I44 disposed on the exterior of the casing. A stem I46 extends into the casing, a compression spring I48 being received thereon. A stop plate I50 supports the spring on the stem in association with the casing for normally biasing the head I44 in covering placement over the apertures I52.

Thus, it is to be seen that there is provided an improved carburetor which, responsive to the operation of the engine, maintains correct mixture of fuel and air in the casing and conveys the proper fuel composition to the engine.

However, since many other purposes and objects of this invention will become apparent to those skilled in the art, upon a perusual of the foregoing description in view of the accompanying drawings, it is to be understood that certain changes, not amounting to invention, may be effected thereon, within the spirit of the invention and within the scope of the appended claim.

Having described the invention, what is claimed as new is:

vA carburetor comprising a housing having an axially reduced open end adapted to be attached to the intake manifold of an internal combustion engine, said housing having an air inlet opening at its other end, a fuel nozzle positioned axially of and within the housing adjacent the air inlet opening, a needle valve in said nozzle, a valve plate positioned transversely in the housing below the fuel nozzle and connected to the needle valve, said valve plate being journaled at one end for vertical swinging movement in the housing responsive to suction in the intake manifold, an actuating arm for said valve plate, a thermostat for actuating the arm, a bellows operatively connected to the reduced end of the housing and responsive to vacuum in the intake manifold, a bar mounted for pivotal movement and connected to said bellows, stop means actuated by the bellows and adjustably secured to said bar for limiting the movement of the actuating arm.

LUCIEN T. ARNOLD.

' REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS I Date Leibing Dec. 28, 1948 

